I have a feature request for Frame Animator. It needs "next" and "previous" buttons, to open the next file in the current directory. The only FRM tool that has this is FRM Viewer, which is why I like it, but it seems to have trouble with some files. I think all FRM viewers should have a next and previous button, because a lot of the time all we want to do is look at a bunch of FRM files. Clicking a next button is a lot easier than doing file->open each time.
And on that note, many of the FO modding tools don't remember what directory I am in, for the next file open, which is very annoying. For example with FUCK, every time I want to do a file open I have to browse to the directory I want. These kind of tools (proto editors) need "next" and "previous" buttons too, or at least their file open dialogs should show the current directory.